Her sister was the first infected. Never found out how it got to her, just found her dead in a tree, deadly spores billowing down from her broken flesh. It should’ve been caught before it got that far along, but somehow they had missed all the signs. Now it was too late. The losses would be catastrophic to the colony as the parasitic scourge starts a full-blown zombie outbreak.

Sounds like a cheap horror flick, right? It’s not. Entire colonies of insects experience this type of catastrophe quite often, actually. Cordyceps mushrooms are the culprit here, and they’re much more terrifying than the mysterious viruses of traditional zombie lore.

By Ian Suzuki [CC BY 3.0 (https://creativecommons.org/licenses/by/3.0)], from Wikimedia Commons

Cordyceps are often recognized as being beneficial, even considered one of the more potent medicinal mushrooms. In fact, there are several types of supplements made from some of the different strains. They are known for providing a boost to your energy and immune system, while also possibly preventing certain cancers. Your heart and lungs can also see the benefits of taking Cordyceps, but despite their potential usefulness, it’s hard to argue with the fact that they spawn in a horrifying manner.

The different strains of Cordyceps have their own choice insect that they prey on. The insect is infected with the spores, and its brain is taken over by the growing mycelium. With ants in particular, once under the control of the brain-killing fungus, the host is compelled to move to a location that will be advantageous for spreading its spores to infect others. If the rest of the colony realizes the insect is infected they’ll try to carry it away it before it can spread the spores to the rest of them. An undiscovered zombified ant that makes it to the point where the Cordyceps want it to go will bite into a plant to anchor itself. Once the ant is dead, the mushroom begins to sprout, and from there the spores are able to spread further and infect more insects. Then the process starts all over.

Personally, I’ve never seen traditional zombies as being super scary. They’re literally just corpses that are falling apart while walking around super slowly. In Naughty Dog’s game The Last of Us, however, the zombies you’re fighting against are a lot more freaky. Cordyceps need a host that is alive, so dead bodies aren’t rising up and transforming. Therefore, instead of being corpses, they are powered-up Cordyceps infected humans.

There are different stages of infection as the mycelium spreads through the host’s body, eventually completely taking over the mind. The first couple of stages are stronger and faster than uninfected humans but have been blinded by the mycelium growing in their eyes.

As the infection spreads; evidenced by the continued sprouting of the mushrooms out of the body, the host gets stronger and slower. Aggression levels rise as well, and any humanity left is wiped out with the death of the brain. The infected still bite, but the plague is also spread through the spores released once they’ve gotten far enough along in their infection, or after they die.

Zombie apocalypses have long been a popular trend, despite their lack of a scientific base. That’s one reason why The Last of Us is so disturbing. As unlikely as it is that Cordyceps will infect humans any time soon, there’s enough science behind the devastation caused to make it seem plausible. For now, though, the annihilation will stick to insects and science fiction.